The older ones
Are just as safe as the new ones...IF you read the book!..You can blow the plug out of a new one just as easy, Two of my Dads sisters were notorious for doing that!! They never read the directions, once my Aunt Mable filled hers full of collard greens...You can imagine what that did to the ceiling...Vomit green spray!!!!LOL, Collards should be, imho, left in the garden!!!!YUCK!, Aunt Beulah always tried to fill up her old Mirro Matic to the top, which the book tells you NEVER to do, I remember once she was going to make Liver Mush."Yeah, its a Southern thing". anyway, she had the pork liver and half of a hog head in the pot, I was about 12 ,and happened to be there that day, I told her, you cant do that, it will blow up...did She listen..NO, did it blow up, YES, GREASY pork broth all over the kitchen!!LOL, Did I have to help clean it up...YES and still had to turn the grinder to grind up all that meat for the liver mush, "Its a little like scrapple except it has liver and is flavored with sage and red pepper, and I could eat my weight in it!!, And I wont eat one bite of liver by itself ..LOL